/*
 * Copyright [2013-2021], Alibaba Group Holding Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.alibaba.polardbx.optimizer.partition.pruning;

import com.alibaba.polardbx.optimizer.context.ExecutionContext;
import com.alibaba.polardbx.optimizer.partition.PartitionInfo;

import java.util.ArrayList;
import java.util.List;

/**
 * @author chenghui.lch
 */
public class UnionStepIntervalMerger implements StepIntervalMerger {

    protected PartitionInfo partInfo;
    protected PartitionPruneStepCombine unionStep;

    public UnionStepIntervalMerger(PartitionPruneStepCombine unionStep, PartitionInfo partInfo) {
        this.unionStep = unionStep;
        this.partInfo = partInfo;
    }

    @Override
    public List<StepIntervalInfo> mergeIntervals(ExecutionContext context, PartPruneStepPruningContext pruningCtx) {
        List<StepIntervalInfo> subRanges = new ArrayList<>();
        for (int i = 0; i < unionStep.getSubSteps().size(); i++) {
            PartitionPruneStep pruneStep = unionStep.getSubSteps().get(i);
            List<StepIntervalInfo> mergedRange = pruneStep.getIntervalMerger().mergeIntervals(context, pruningCtx);
            subRanges.addAll(mergedRange);
        }
        List<StepIntervalInfo> resultRanges = PartitionPruneStepIntervalAnalyzer
            .mergeIntervalsForUnionStep(partInfo, subRanges);
        return resultRanges;
    }

    @Override
    public PartitionInfo getPartInfo() {
        return partInfo;
    }

    public void setPartInfo(PartitionInfo partInfo) {
        this.partInfo = partInfo;
    }
}
